Method and System for Building Modular Structures from Which Oil and Gas Wells are Drilled

ABSTRACT

A method and system for building modular platform structures from which oil and gas wells are drilled and maintained is disclosed, wherein a plurality of easily transportable, multifunctional platform modules are interconnected on-site to form a unitary platform structure. The interconnected platform modules are elevated above a ground surface on one or more legs coupled to at least one of the platform modules. The elevated, interconnected platform modules support both drilling and production operations in land-based, arctic, inaccessible, near-offshore and environmentally sensitive locations.

CROSS-REFERENCE TO RELATED APPLICATIONS

The instant application is a continuation of 11/366,188, filed Mar. 2,2006, still pending, which is a continuation of 10/434,436, filed May 8,2003, now abandoned, which is a continuation-in-part of U.S. applicationSer. No. 10/142,741, filed May 8, 2002, now issued as U.S. Pat. No.6,745,852 B2, to which application priority is hereby claimed.

FIELD OF THE INVENTION

The present invention relates generally to the field of oil and gasdrilling and production. In a specific, non-limiting, embodiment, theinvention comprises a method and system for building modular platformstructures from which oil and gas wells are drilled and maintained inremote or environmentally sensitive locations while minimizing grounddisturbance beneath the structures.

DESCRIPTION OF THE PRIOR ART

The drilling and maintenance of land oil and gas wells requires adesignated area on which to dispose a drilling rig and associatedsupport equipment. Drilling locations are accessed by a variety ofmeans, for example, by roadway, waterway or other suitable accessroutes. In particularly remote locations, access to a drilling site issometimes achieved via airlift, either by helicopter, fixed wingaircraft, or both.

Some potential oil and gas exploration and development sites areconstrained by special circumstances that make transportation ofdrilling equipment to the drilling site difficult or impossible. Forexample, oil and gas may be found in terrain with near-surface wateraccumulations, such as swamps, tidal flats, jungles, stranded lakes,tundra, muskegs, and permafrost regions. In the case of swamps, muskegs,and tidal flats, the ground is generally too soft to support trucks andother heavy equipment. In the case of tundra and permafrost regions,heavy equipment can be supported only during the winter months.

Moreover, certain oil and gas drilling sites are disposed inenvironmentally sensitive regions, such that surface access byconventional transport vehicles can damage the terrain or affectwildlife breeding areas and/or migration paths. Such environmentalproblems are particularly acute in, for example, arctic tundra andpermafrost regions. In such areas, road construction is eitherprohibited or limited to temporary seasonal access.

For example, substantial oil and gas reserves exist in the far northernreaches of Canada and Alaska. However, drilling in such regions presentssubstantial engineering and environmental challenges. The current art ofdrilling onshore in arctic tundra is enabled by the use of specialpurpose vehicles, such as Rolligons™, that can travel across ice roadsbuilt on frozen tundra.

Ice roads are built by spraying water on a frozen surface at very coldtemperatures. Ice roads are typically constructed about 35 feet wide and6 inches thick. At strategic locations, the ice roads are made wider toallow for staging and turn around capabilities.

Land drilling in arctic regions is currently performed on square-shapedice pads, the dimensions of which are about 500 feet on a side;typically, the ice pads comprise 6-inch thick sheets of ice. The rigitself is built on a thicker ice pad, for example, a 6 to 12-inch thickpad. A reserve pit is typically constructed with about a two-footthickness of ice, plus an ice berm, which provides at least two feet offreeboard space above the pit's contents. These reserve pits, which arealso referred to as ice-bermed drilling waste storage cells, typicallyhave a volume capacity of about 45,000 cubic feet, suitable foraccumulating and storing about 15,000 cubic feet of cuttings andeffluent. In addition to the ice roads and the drilling pad, an arcticdrilling location typically includes an airstrip, which is essentially abroad, extended ice road formed as described above.

Ice roads can run from tens of miles to hundreds of miles in length,depending upon the proximity or remoteness of the existinginfrastructure. The fresh water needed for the ice to construct theroads and pads is usually obtained from lakes and ponds that aretypically numerous in such regions. The construction of an ice roadtypically requires around 1,000,000 gallons of water per linear mile.Over the course of a winter season, another 200,000 gallons or so permile are required to maintain the ice road. Therefore, for a ten-mileice road, a total of 2,000,000 gallons of water would have to be pickedup from nearby lakes and sprayed on the selected route to maintain thestructural integrity of the ice road.

An airstrip requires about 2,000,000 gallons of water per mile toconstruct, and a single drill pad requires about 1,700,000 gallons. Fordrilling operations on a typical 30-day well, an additional 20,000gallons per day are required, for a total of about 600,000 gallons forthe well. A 75-man camp requires another 5,000 gallons per day, or150,000 gallons per month, to support. Sometimes, there are two to fourwells drilled from each pad, frequently with a geological side-track ineach well, and thus even more water is required to maintain the site.

Thus, for a winter drilling operation involving, for example, 7 wells,75 miles of road, 7 drilling pads, an airstrip, a 75-man camp, and thedrilling of 5 new wells plus re-entry of two wells left incomplete, thefresh water requirements are on the order of tens of millions ofgallons.

Currently, arctic land drilling operations are conducted only during thewinter months. Typically, roadwork commences in the beginning ofJanuary, simultaneous with location building and rig mobilization. Dueto the lack of ice roads, initial mobilizations are done with specialpurpose vehicles such as Rolligons™, suitable for use even in remoteregions of the arctic tundra. Drilling operations typically commencearound the beginning of February, and last until the middle of April, atwhich time all equipment and waste-pit contents must be removed beforethe ice pads and roads melt. However, in the Alaskan North Slope, thetundra is closed to all traffic from May 15 to July 1 due to nestingbirds. If the breakup is late, then drilling prospects can be fullytested before demobilizing the rig. Otherwise, the entire infrastructurehas to be removed, and then rebuilt the following season.

From the foregoing, it is seen that there are several drawbacksassociated with current arctic drilling technology. Huge volumes ofwater are pumped out of ponds and lakes and then allowed to thaw out andbecome surface run-off again. Also, the ice roads can becomecontaminated with lube oil and grease, antifreeze, and rubber products.In addition to the environmental impact, the economic costs associatedwith drilling in arctic regions are very high. Operations may beconducted only during the coldest parts of the year, which is typicallyless than 4 or 5 months. Thus, actual drilling and testing may beconducted in a window of only two to four months or less. Therefore,development can occur during less than half the year. At the beginningof each drilling season, the roads and pads must all be rebuilt, andequipment must again be transported to and removed from the site, all atsubstantial financial and environmental cost.

SUMMARY OF THE INVENTION

According to one example embodiment, the present invention provides amethod and system for building interconnectible platform modules fromwhich oil and gas wells are drilled and maintained, either on land or inrelatively shallow water, for example, in water having a minimum depthof about 8 feet or less. Thus, the invention admits to practice in manydifferent drilling and production environments, for example, dry land,swamps, marshes, tundra, permafrost regions, shallow lakes,near-offshore sites, etc.

In one example embodiment, the interconnectible platform modules andassociated drilling facility are disposed above the surface of theground. In other embodiments, modular platforms suitable foraccommodating other equipment and structures besides a drilling facilityare provided. In various other embodiments, the modular platformstructures are transportable to a drilling site by a wide variety oftransport means, for example, by truck, railcar, boat, hovercraft,helicopter, etc. In still other embodiments, the modular platformstructures are multifunctional, and can be interconnected in a varietyof ways to form different portions of a drilling site, for example, adrilling platform, a storage platform for auxiliary drilling equipment,a waste retention platform disposed beneath a drilling platform suitablefor accumulating and storing cuttings and production effluent, etc.

According to one example of the invention, a modular platform structurecomprises a plurality of expandable, multifunctional platform modules,which are interconnected to one another on-site to form a unitaryplatform structure. In some embodiments, legs for affixing theinterconnected platform modules have already been embedded in the groundor otherwise installed at the drilling site prior to delivery of theplatform modules. In other embodiments, modular sections of the platformstructure are assembled in a remote location and then transported to thedrilling site, where the assembled sections are connected to one anotherand secured in place by legs that have been embedded in the ground priorto delivery. In still other embodiments, the legs are driven orotherwise installed after the modules have been delivered to thedrilling site by, for example, a crane or other suitable device.

In other example embodiments, the modular sections are connected suchthat portions of the platform structure are affixed at differentelevation levels, so that certain portions of the structure are isolatedfor drilling and other operations, while other portions are disposed forsupport functions such as material storage, housing, waste collection,etc. For example, in some embodiments of the invention, two or morevertical tiers of platform modules (i.e., one installed above or nearlyabove the other) are affixed to common leg members to create platformwork spaces dedicated to various functions associated with oil and gasdrilling and production.

In various other example embodiments, the interconnected platformmodules are assembled on-site, and then elevated above the groundsurface on one or more legs coupled to at least one of the platformmodules. In still other embodiments, a plurality of platform modules areconnected beneath a main drilling platform, and support the drilling andauxiliary operations disposed above, as well as other structures, forexample, storage facilities, living quarters, etc.

Regardless of whether platform assembly occurs on-site or in sectionsfrom a remote location, the modular platform structures are of a sizeand shape capable of being transported to a drilling site by a varietyof means, for example, truck, railcar, helicopter, hovercraft, etc.According to a further example embodiment, the modules are alsoconfigured to float, so they can be towed over water to the drillinglocation by a water-borne vessel such as a skiff or hovercraft, etc.

According to one example embodiment, some of the platform modulescomprise structural, weight-bearing members for supporting derricks andheavy equipment, such as draw-works, engines, pumps, cranes, etc. Infurther embodiments, some of the platform modules comprise specialpurpose modules, for example, pipe storage modules; material storagemodules for storing materials, for example, cement, drilling fluid,fuel, water, etc.; and equipment modules for housing equipment, forexample, generators, fluid handling equipment, etc. Other exampleembodiments comprise modules formed with legs affixed in desiredlocations, whereas in other example embodiments the platform moduleshave spaces cut out from the corners (or elsewhere) where legs can befastened (or passed through) and then connected to one or more receivingmembers disposed on the platform modules. In some example embodiments,the legs are attached to the platform modules using the same types ofconnectors as are employed to connect the modules to one another,although in other examples the legs are affixed using a differentconnection means, for example, a high-load heavy-duty fastener,depending on the weight load to which the module will ultimately besubjected. In other embodiments, the legs themselves are load bearing,and the load imposed by equipment or a structure installed above isdistributed across both the legs and connected platform modules; instill other embodiments, the load bearing legs bear the entire load ofequipment or a structure installed above.

In one specific embodiment of the invention, the legs are adapted to bedriven or otherwise inserted into the ground to support the elevateddrilling platform. In further embodiments, leg members terminate at afoot structure, for example, a flat, metal brace formed eitherstructurally integral with or bracketed to an outer portion of the leg,used to support the platform structure. In other embodiments, a footstructure is used in conjunction with other bracing techniques, forexample, by passing a leg through the body of a foot structure anddriving the lower end of the leg into a shallow hole in which theterminus point is distended.

In still further embodiments, the legs comprise sections that areconnected together to form legs of a desired length. In another exampleembodiment, the legs are all approximately the same length after theplatform structure is assembled, while in still other embodiments thelegs are of different lengths to accommodate various elevationdifferences between and amongst various portions of the platform and/orinconsistent terrain elevations below the structure.

In further embodiments, the legs include passageways for the flow offluids such as air, refrigerants, cement, etc. In still furtherembodiments, the legs comprise a bladder that is inflated with air orother fluids to provide increased support for the legs. In otherexamples of the invention, the bladder extends out of the bottom of theleg into the ground as it is being inflated to provide increasedsupport.

In a presently preferred embodiment of the invention, the legs areremovable from the ground when drilling is complete, so as to minimizeground disturbance around the drilling site. In other embodiments, thelegs disassemble at a joint or fastening, etc., disposed near groundlevel, or in a still more preferred embodiment, beneath ground level, sothat the only portion of a leg that remains when the site is evacuatedis embedded in the ground and can later be covered over with cement,dirt, etc., as desired.

According to an example method of the invention, a plurality of platformmodules are transported to a first drilling location using a knowntransportation means. The platform modules are easily transportable by,for example, helicopter, railcar, or hovercraft, etc., or by a specialpurpose vehicle adapted to minimize harm to the environment while inpassage when necessary. The platform modules are suitable for mutualinterconnection, and are assembled either on-site or in sections at aremote location prior to transport. In one embodiment of the invention,functionally related portions of the structure are connected prior totransport, so that sections that will later be adjoining, e.g., housingunits, equipment storage platforms, waste collection units, etc., arealready connected prior to transport.

According to one example method, a modular structure is assembledon-site and affixed to legs driven into the ground prior to delivery ofthe modules to the drilling site; this portion of the structure is thenelevated over the drilling location. According to various other methods,drilling equipment is installed on the elevated modular structure,either prior to or following elevation over the drilling site. After thedrilling equipment is installed, one or more wells are drilled.

According to a method of the invention particularly useful in hostileclimates, for example, in arctic regions, the modules are transported tothe drilling site, and a first platform structure is built and elevatedduring the winter season, while the ground can still support the weightof transport vehicles and the drilling equipment. After the platformstructure has been elevated, drilling continues throughout the year.

According to a still further method of the invention, a second platformmodule is transported to a second drilling location. The second platformmodule is affixed to one or more legs, and elevated to form either acomplete second drilling platform or the nucleus for a second drillingplatform. When it is desired to drill from the second drilling platform,all or some of the drilling equipment is transported from the firstplatform structure to the second platform structure, and then installedon the second drilling platform. In a further example embodiment, thedrilling equipment is transferred from a nearby storage area, forexample, the first drilling platform or a nearby transport vessel, etc.According to a still further example embodiment, the drilling equipmentis used to drill wells from the second platform as part of amulti-season, multi-location drilling program, or as a relief well forwells drilled from the first platform.

In other example embodiments, the platform sections are verticallymodular, such that a first elevated platform section is affixed to thesame legs as a second platform section disposed above (or nearly so).According to further embodiments of the invention, drilling equipmentstored on a lower platform module, for example, drill bits, drillstring, etc., is passed from the lower platform to an upper platform foruse with drilling, while cuttings and effluent generated by operationson the upper platform section are allowed to fall through a grating, ordrain, etc., so as to be accumulated and stored either on or within thelower platform modules, thereby reducing the amount of waste generatedduring the drilling and production process that would otherwise fall tothe ground. In other embodiments, the entire platform structure (or, incertain instances, portions of the platform structure), has a secondarywaste retention device, for example, a tarpaulin or canvas sheet, etc.,disposed beneath it to catch and store cuttings or effluent, etc., thatfall from above. In other embodiments, the secondary waste retentiondevice can itself serve as a redundant platform space, suitable forstoring equipment that is not currently in use, or for capturingequipment or other items that fall from the platform and would otherwiseland in the water below the drilling site. In still further embodiments,the secondary waste retention device has a perimeter boundary widthgreater than the width of the drilling platform, so that waste andeffluent ejected from the site horizontally are also captured.

As will be appreciated by one of ordinary skill in the appropriate arts,the transportable, modular platform sections disclosed herein can beconnected into many shapes and sizes, and can be employed to form eitheran essentially unitary drilling structure or a number of smallerstructures erected nearby and serviced in a hop-scotch fashion (or acombination of the two approaches), to create a movable series ofland-based, semi-permanent structures that will improve the overallefficiency of drilling platforms disposed in remote or inaccessiblelocations, minimize the environmental impact of associated drilling andproduction operations, and which will later be removed withoutsignificantly disturbing the ground surface beneath the operationsite(s). The multifunctional nature of the interconnectible modulesencourages efficient equipment disposition between and amongstneighboring drilling sites, and reduces the impact of associateddrilling operations on the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a drilling platform according to thepresent invention.

FIG. 2 is a perspective view of a plurality of platform modules and legsawaiting assembly according to the present invention.

FIG. 3 is a perspective view of the platform modules and legs of FIG. 2assembled according to the present invention.

FIGS. 4A-4C are perspective views of examples of special purposeplatform modules according to the present invention.

FIGS. 5A and 5B are perspective views of alternative leg attachmentarrangements according to the present invention.

FIGS. 6A and 6B illustrate elevation of assembled platform modulesaccording to the present invention.

FIGS. 7A-7E illustrate features of platform legs according to thepresent invention.

FIG. 8 illustrates renewable energy production facilities installed on aplatform according to the present invention.

FIGS. 9A-9D illustrate a multiple well drilling program according to thepresent invention.

FIGS. 10A-10C illustrate a further multiple well drilling programaccording to the present invention.

DETAILED DESCRIPTION

Referring now to the example embodiment shown in FIG. 1, a drillingplatform 11 is illustrated comprising a plurality of interconnectedplatform modules 13 elevated above the ground on a plurality of legs 15.According to a further embodiment of the invention, platform 11 isadapted to support various types of equipment and facilities used in oiland gas drilling or production operations, for example, a derrick 17, acrane 19, a helicopter pad 21, a drilling fluid handling enclosure 23,bulk storage tanks 25, and oilfield tubular goods 27. The equipment andfacilities illustrated in FIG. 1 are non-limiting, and those of ordinaryskill in the art will appreciate that many other types of facilities andequipment may be included on platform 11 without departing from thescope or spirit of the present invention.

According to a further example embodiment, drilling platform 11 isconstructed by transporting a plurality of interconnectible platformmodules 13 and a plurality of legs 15 to a drilling site, and thenassembling the various modules 13 and legs 15 into an essentiallyunitary structure. Platform modules 13 are of a size and weight as to betransportable to the drilling site by a wide variety of transport means,for example, by helicopter, truck, railcar, hovercraft, etc. In theexample embodiment illustrated in FIG. 1, interconnectible platformmodules 13 are constructed as box-like structures made of steel or othermaterials, for example, composite metals, etc., and are about 40 feet inlength and from 10 to 20 feet in width. However, the shapes and sizes ofthe modules described herein are solely for the purpose of example andillustration, and those of ordinary skill in the art will recognize thatthe modules may be of other shapes, sizes and configurations, withoutlimiting the scope of the invention. For example, platform modules maybe formed without a load bearing bottom member, or even lacking a bottomentirely, without departing from the scope of the present invention.

According to one embodiment of the invention, some of the platformmodules comprise structural, weight-bearing members for supportingderricks and heavy equipment, such as draw-works, motors, engines,pumps, cranes, etc. In further embodiments, some of the platform modulescomprise special purpose modules, for example, pipe storage modules;material storage modules for storing, for example, cement, drillingfluid, fuel, water, etc.; and equipment modules for storing equipment,for example, generators, fluid handling equipment, etc.

According to one embodiment of the invention, legs 15 comprise tubularmembers with joints at their ends connected together to form legs ofappropriate lengths. However, the legs may be of other cross-sections orconfigurations, for example, driven piles, etc. In one specific exampleembodiment, the legs are adapted to be driven or otherwise inserted intothe ground to support an elevated drilling platform or otherweight-bearing structures. In other example embodiments, the load of aweight-bearing structure is distributed by affixing the structure to oneor more of the legs as well as the modular platform structures. In stillother embodiments, various structures are entirely affixed to the legsinstead of the platform structures as a matter of convenience, forexample, a communications center affixed at about eye level on a legthat extends vertically between two or more levels of the platform.

In further embodiments, the legs comprise sections that are connectedtogether to form legs of a desired length. In another exampleembodiment, the legs are all approximately the same length after theplatform structure is assembled, while in still other embodiments thelegs are of different lengths to accommodate various elevationdifferences between and amongst various portions of the platform and/orinconsistent terrain elevations below the structure. In furtherembodiments, the legs include passageways for the flow of fluids such asair, refrigerants, cement, etc. In still further example embodiments,the legs comprise a bladder that may be inflated with air or otherfluids to provide increased support for the legs. In other examples ofthe invention, the bladder extends out of the bottom of the leg into theground as it is being inflated to provide increased support.

Still further example embodiments comprise platform modules formed withlegs already affixed in desired locations when the platform modules aredelivered to the drilling site, whereas in other example embodimentsmodules have spaces cut out from the corners (or elsewhere) where legsare fastened (or passed through) and then connected to one or morereceiving members disposed on the modules. In some example embodiments,the legs are attached to the modules using the same types of connectorsas are employed to connect the modules to one another, although in otherexamples the legs are affixed using a different connection means,depending on the weight load to which the module will ultimately besubjected.

According to a presently preferred embodiment of the invention, saidplurality of legs 15 are removable from the ground when drillingoperations have been completed. In a further example embodiment, thelegs are detachable at a joint or fastening disposed near ground level,and are detached at said joint or fastener after drilling is complete,leaving only an lowermost portion of said plurality of legs 15 embeddedin the ground, so as to minimize ground disturbance around the drillingsite. According to a further aspect of the invention, the portions oflegs 15 left embedded in the ground after detachment are covered over bycement or dirt, etc., when the site is ultimately evacuated.

In still further embodiments, the entire platform structure (or, incertain instances, portions of the platform structure), has a secondarywaste retention device (not shown), for example, a tarpaulin or canvassheet, etc., disposed beneath it to catch and store cuttings oreffluent, etc., that fall from above. In other embodiments, thesecondary waste retention device can itself serve as a redundantplatform space, suitable, for example, for storing equipment that is notcurrently in use, or for capturing equipment or other items that fallfrom the platform and would otherwise land on the ground or in the waterbelow the drilling site. In still further embodiments, the secondarywaste retention device has a perimeter boundary width greater than thewidth of the drilling platform, so that waste and effluent ejected fromthe site in a horizontal direction may also captured.

Referring now to the example shown in FIG. 3, the platform modules 13are interconnected and at least partially raised on legs 15. Accordingto one embodiment of the invention, a complete drilling platform isassembled, formed from modules 13 while the structure is still on theground, and then lifted as a unit on a plurality of legs 15. In anotherexample embodiment, one or more of modules 13 are interconnected, andthen elevated to form a nucleus about which other modules are elevatedand connected together.

Referring now to the embodiments of the invention illustrated in FIGS.4A-4C, various platform modules according to the present invention areprovided to partially demonstrate the platform modules' multifunctionalnature. For example, in FIG. 4A, there is illustrated a fluid storagemodule 13 a. In one embodiment of the invention, fluid storage module 13a includes at its corners holes 27 for the insertion of legs. In otherexample embodiments, fluid storage module 13 a is essentially a box-likehollow tank that includes a port or pipe 29, which is useful for theflow of fluids or waste into and out of the interior of fluid storagemodule 13 a. In various other embodiments, fluid storage modules 13 aare used, for example, in place of a conventional reserve pit to drainand/or store effluent produced by a rig during production, or to flushand store cuttings and other waste products from the drilling platform.In one embodiment of the invention especially useful in environmentallysensitive drilling regions, fluid storage modules 13 a are hauled awaywith the contents, e.g., cuttings, effluent, etc., contained inside,thereby eliminating the handling of waste fluids and reducing the riskof spillage into the surrounding environment.

Referring now to the example embodiment of FIG. 4B, a structural,load-bearing module 13 b is depicted. In some example embodiments,load-bearing module 13 b is a box-like structure having leg holes 31disposed in its corners, though in other embodiments load-bearing module13 b is constructed without providing receiving members for legs and isinstead adapted only for interconnection with other modules. Accordingto one example embodiment, load-bearing module 13 b includes internalstructural reinforcement plating 33 to provide greater strength and lendgreater structural integrity to module 13 b. Internal structuralreinforcement plating 33 is illustrated solely for purposes of example,and other reinforcement structures, for example, trusses, I-beams,honey-combs, etc., are utilized as required. In still further exampleembodiments, module 13 b is constructed into different shapes to formvarious types of structures, for example, floors for housing units,support members for derricks and other heavy pieces of drillingequipment, etc. In still further embodiments, a variety of differentmaterials, for example, Aluminum, Titanium, steel, composite metals,etc., are used to make the platform modules 13.

Referring now to the example embodiment illustrated in FIG. 4C, abox-like equipment module 13 c is provided, wherein various types ofequipment adapted for use in drilling or auxiliary operations aredisposed. According to one example embodiment, the equipment includescentrifuges 37, powered by motors 39 connected by various manifolds 41,for controlling solids and fluid flow. In further example embodiments,equipment modules 13 c comprise other types of equipment, e.g., pumps,hydrocyclones, drilling string, etc. From the foregoing, it should beapparent to one of ordinary skill in the art that the various types ofequipment modules 13 c are assembled to provide both a structuralplatform and a means for storing basic equipment and services for useduring drilling operations.

Referring now to FIGS. 5A and 5B, there are shown various exampleembodiments for the connection of a leg to a platform module. In FIG.5A, a module 13 d comprises one or more tubular leg holes 43 disposed inthe corners of said module. A leg (not shown) is simply adapted to slidethrough leg hole 43. In various example embodiments, the leg is fixed inplace with respect to leg-hole 43 by any suitable means, such as slips,pins, flanges, or the like. In the example of FIG. 5B, an exampleembodiment of module 13 e is shown comprising a right angle cutout 45formed at one or more corners of the module. In some embodiments, cutout45 is adapted to receive either a blank insert 47 or a leg-engaginginsert 49. In other embodiments, blank insert 47 may be fastened intonotch 45 in the event that no leg needs to be positioned at a corner ofmodule 13. In further embodiments, leg-engaging insert 49 includes abore 51 having a shape adapted to slidingly engage a leg (not shown). Instill further embodiments, one of either blank insert 47 or leg-engaginginsert 49, as appropriate, is fastened into notch 45 with bolts or othersuitable fastening means.

Referring now to the examples illustrated in FIGS. 6A and 6B, a seriesof interconnected modules 13 f-13 j are depicted in structuralcommunication with a plurality of legs 15. According to one embodimentof the invention, a sufficient number of legs 15 is selected in order toprovide adequate support for both the interconnected modules 13 f-13 jand the equipment to be supported thereby (not shown). According to oneexample embodiment, modules 13 f-13 j in FIG. 6 are of the typeillustrated in FIG. 5B. Accordingly, blank inserts 47 or leg-engaginginserts 49 are affixed at corners of the modules 13, as appropriate. Infurther example embodiments, legs of appropriate lengths are insertedthrough the leg inserts and then drilled, driven or otherwise insertedto an appropriate depth in the ground. In still further embodiments, thelegs include passageways for the flow of fluids such as air,refrigerants, cement, etc. In still further embodiments, the legscomprise a bladder that is inflated with air or other fluids to provideincreased support for the legs. In other examples of the invention, thebladder extends out of the bottom of the leg into the ground as it isbeing inflated to provide increased support.

In a presently preferred embodiment of the invention, the legs areremovable from the ground when drilling is complete, so as to minimizeground disturbance around the drilling site. In other embodiments, thelegs disassemble at a joint or fastening, etc., disposed near groundlevel, or in a still more preferred embodiment, beneath ground level, sothat the only portion of a leg that remains when the site is evacuatedis embedded in the ground and can later be covered over with cement,dirt, etc., as desired.

According to one example embodiment, after the legs 15 have beensecured, the interconnected modules 13 f-13 j are raised, to a positionas shown in FIG. 6B. In the embodiment shown in FIG. 6A, liftingmechanisms 55 are employed to assist in lifting the interconnectedplatform modules. Appropriate lifting mechanisms may comprise, forexample, hydraulic or mechanical lifting mechanisms to assist in liftingthe platform modules. In other example embodiments, the interconnectedmodules are lifted with, for example, cranes, helicopters, or othersuitable lifting devices, as would be apparent to one of ordinary skillin the art. Although legs 15 are illustrated as being tubular in FIGS.6A and 6B, other cross-sections and leg structures are also employedaccording to further embodiments of the present invention.

Referring now to the examples of FIGS. 7A-7E, various details of legsaccording to the present invention are illustrated. As seen in theexample of FIG. 7A, a portion of a module 13 n is shown elevated withrespect to a leg 15. In the illustrated embodiment, leg 15 n is atubular member having a main flow area 61 and an annular flow area 63.Leg 15 n is thus configured to accommodate a circulating flow of fluids,for example, refrigerants or water, etc. According to certainembodiments, leg 15 n includes a retrievable section 65 disposed at itslower end to allow the pumping of cement or the circulation of otherfluids down the main flow area 61. In the embodiment illustrated in FIG.7A, cement 67, or another deposit of material, for example, acombination of water and stone, is pumped into the ground belowretrievable 65. Cement 67 provides a footing for leg 15 n.

As indicated by pipe section 69, additional lengths of pipe are, in someembodiments, inserted to lengthen leg 15 n in order to providesufficient support for module 13. According to further exampleembodiments, leg 15 n may include a separable connection 71, forexample, a fastener, which allows the lower end of leg 15 n to separateand be left in the ground when the platform is ultimately removed fromthe site. In certain environmentally sensitive environments, the lowerend of the leg left embedded in the ground is covered over by, forexample, cement or dirt, etc.

In the example of FIG. 7B, a configuration is shown in which a leg 15 mincludes at its lower end an inflatable bladder 73. According to someembodiments of the invention, the inflatable bladder 73 is inflated witha fluid, for example, air, cement, or another suitable fluid, to compactthe earth around the lower end of leg 15 m and provide an additionalfooting for leg 15 m.

In the examples of FIGS. 7C and 7D (top view), an embodiment is shown inwhich a leg member 15 is supported by a foot structure 74, for example,a flat, metal brace bracketed to an outer portion of leg 15, used tosupport the platform structure. As seen in the embodiment of FIG. 7E,foot structure 74 can be used in conjunction with other bracingtechniques, for example, the embodiments shown in FIGS. 7A and 7B, orwith a shallow hole in which the terminus point of leg 15 is distended.

Referring now to the example embodiment of FIG. 8, renewable energysources, for example, solar panel array 75, wind mill power generators77, etc., are supported by the platform. In further embodiments,renewable power sources 75 and 77 provide energy for a variety ofdrilling-related equipment, for example, pumps, compressors,centrifuges, etc. According to still further embodiments, renewablepower sources 75 and 77 also provide energy for hydrate production. Whenso employed, renewable energy sources minimize fuel requirements for thedrilling platform while also minimizing air pollution and conservingproduction fluids.

Referring now to the embodiments of FIGS. 9A-9B, there is illustrated amulti-year, multi-seasonal drilling program according to the presentinvention. In the embodiment of FIG. 9A, three platforms 11 a-11 c aretransported to and erected at various, suitably spaced, locations. Inembodiments comprising an arctic drilling program, platforms 11 a-11 care transported and installed during the winter using aircraft, forexample, helicopters; or surface vehicles on ice roads, for example,trucks or Rolligons™; or a combination thereof. In a specific,non-limiting, example embodiment, platform 11 b is positioned 100 milesfrom platform 11 a, and platform 11 c is positioned 300 miles fromplatform 11 b. The distances recited herein are solely for purposes ofillustration, and other spacings and numbers of platforms can also beprovided as desired.

As shown in the example of FIG. 9A, platform 11 a has installed thereona complete set of drilling equipment, for example, a derrick 17, a crane19, and the other equipment described with respect to FIG. 1. In theexample embodiments shown in FIGS. 9A-9B, platforms 11 b and 11 c do nothave a complete set of drilling equipment installed thereon, instead,comprising only structural platform features and other sets of fixedequipment, for example, pumps, manifolds, generators, etc. According toone example embodiment, platforms 11 b and 11 c await installation ofadditional drilling equipment. According to the present invention, oneor more wells are drilled from platform 11, while platforms 11 b and 11c remain idle.

Referring now to the example embodiment of FIG. 9B, after the well orwells drilled from platform 11 a are complete, the necessary drillingequipment is transported from platform 11 a to platform 11 b. In theillustrated embodiment, the drilling equipment is transferred usingaircraft such as helicopters. Since the transport is by air, thetransfer may occur during a warm season. Also, since platform 11 b iselevated above the ground surface on legs that are supported below thefall thaw zone, operations on platform 11 b can be conducted during thewarm season. The transport by air is for purposes of illustration, andthose of ordinary skill in the pertinent arts will appreciate that indiffering terrains and seasons, equipment transport may be by a varietyof transport means, for example, truck, railcar, hovercraft, Rolligon™vehicle, barge, surface effect vehicle, etc.

According to a further embodiment of the invention, after the drillingequipment has been transported to and installed upon platform 11 b, theremaining structural assembly of platform 11 a is left idle. In otherembodiments, after drilling equipment is completely installed onplatform 11 b, drilling of one or more wells commences, as shown, forexample, in the embodiment of FIG. 9C.

In a still further embodiment, after drilling from platform 11 b hasbeen completed, drilling equipment is transferred from platform 11 b toplatform 11 c as illustrated, for example, in FIG. 9D. Again, in thedepicted embodiment, the drilling equipment is preferably transportedfrom platform 11 b to platform 11 c by aircraft, though differingterrain and operating environments will call for other transport meansas described above. In each of the example embodiments, transportationof drilling equipment may occur during any season of the year. Thus,according to the invention illustrated in FIGS. 9A-9B, installation andoperation of drilling equipment is also performed during any season ofthe year and not only during the coldest parts of the year. Thus, thetime spent drilling may be doubled or even tripled according to themethod of the present invention without substantial additionalenvironmental impact. Also, the method and system of the presentinvention enable wells to be drilled and completed in the normal courseof operations without the possibility of having to transport equipmentto and from a drilling site multiple times.

Referring now to the example embodiment depicted in FIG. 10A, a primaryplatform 11 a is transported to and erected at a first location, and asecondary platform 11 b is transported to and erected at a secondlocation geographically spaced apart from the first location. In theexample of FIG. 10A, platform 11 a is a complete drilling platform,while platform 11 b comprises only a single module erected on legs.According to some embodiments, platform 11 b provides a nucleus aboutwhich a second complete platform is erected when the need arises. Thesystem illustrated in FIGS. 10A-10C is well adapted, for example, to thedrilling of a relief well for another well drilled from platform 11 a.

Referring to the example embodiment of FIG. 10B, when it is necessary ordesired to drill a well from the location of platform 11 b, platformmodules are transported to the location of platform 11 b by aircraft,for example, by helicopter. According to a further embodiment, workersuse previously installed modules as a base for installing new modules.According to a still further embodiment, a crane is positioned on theinstalled modules and skidded about to drill or drive legs and positionnew modules. As shown in the example embodiment of FIG. 10C, after thesecond platform 11 b is completed, drilling equipment is transportedthereto by helicopter or another suitable transport means.

The foregoing specification is provided for illustrative purposes only,and is not intended to describe all possible aspects of the presentinvention. Moreover, while the invention has been shown and described indetail with respect to several exemplary embodiments, those of ordinaryskill in the pertinent arts will appreciate that minor changes to thedescription, and various other modifications, omissions and additionsmay also be made without departing from either the spirit or scopethereof.

1. A method of drilling wells, wherein said wells are drilled atdrilling sites have a water depth of less than about seven feet, saidmethod comprising: constructing a plurality of modular drillingplatforms at a plurality of drilling sites; installing a set of drillingequipment on a first of said modular drilling platforms; drilling a wellfrom said first modular drilling platform; transporting said set ofdrilling equipment from said first modular drilling platform to a secondof said modular drilling platforms; installing said set of drillingequipment on said second modular drilling platform; and drilling a wellfrom said second modular drilling platform.
 2. The method of drillingwells of claim 1, wherein said method further comprises: transportingsaid set of drilling equipment from said second modular drillingplatform to a third of said modular drilling platforms; installing saidset of drilling equipment on said third modular drilling platform; anddrilling a well from said third modular drilling platform.
 3. The methodof drilling wells of claim 1, wherein said constructing a plurality ofmodular drilling platforms further comprises: transporting at least oneplatform module to at least one of said plurality of drilling sites; andelevating said at least one platform module over said at least one ofsaid plurality of drilling sites.
 4. The method of drilling wells ofclaim 3, wherein said transporting at least one platform module furthercomprises transporting a plurality of mutually interconnectible platformmodules.
 5. The method of drilling wells of claim 3, wherein saidtransporting at least one platform module further comprises transportinga plurality of multifunctional platform modules.
 6. The method ofdrilling wells of claim 5, wherein said transporting a plurality ofmultifunctional platform modules further comprises transporting at leastone waste retention platform module.
 7. The method of drilling wells ofclaim 3, wherein said elevating said at least one platform modulefurther comprises: transporting at least one leg to said at least one ofsaid drilling sites; and raising said at least one platform module onsaid at least one leg.
 8. The method of drilling wells of claim 7,wherein said elevating said at least one platform module furthercomprises inserting said at least one leg into a surface region disposedbeneath said drilling site.
 9. The method of drilling wells of claim 8,wherein said inserting said at least one leg into said surface regionfurther comprises driving said at least one leg into said surfaceregion.
 10. The method of drilling wells of claim 8, said method furthercomprising injecting a fluid into said at least one leg.
 11. The methodof drilling wells of claim 10, wherein said fluid further comprisescement.
 12. A system for drilling wells, wherein said wells are drilledat drilling sites have a water depth of less than about seven feet, saidsystem comprising: a plurality of interconnected platform modules; atleast one leg coupled to at least one of said plurality ofinterconnected platform modules to support said plurality ofinterconnected platform modules above a surface region; and drillingequipment supported by said plurality of interconnected platformmodules.
 13. The system of claim 12, wherein each of said platformmodules is transportable by aircraft.
 14. The system of claim 12,wherein each of said platform modules is transportable by boat.
 15. Thesystem of claim 12, wherein each of said platform modules istransportable by at least one of a truck, a railcar, a hovercraft, and ahelicopter.
 16. The system of claim 12, wherein at least one of saidplurality of interconnected platform modules further comprises: a bodyportion; and a leg attachment member coupled to said body portion. 17.The system of claim 16, wherein said leg attachment member isstructurally integral with said body portion.
 18. The system of claim16, wherein said leg attachment member is separable from said bodyportion.